At its Middlemarch Business Park headquarters behind Coventry airport, NCMT (024 7651 6600) offered up demonstrations of grinding, turning and milling on the Japanese-built machines it represents in the UK: Okamoto, Makino and Okuma.
The focus of the event, the company's first on such a large scale, was not so much on new machines – although there was the UK debut of the Okuma Multus U3000W multi-tasking turning centre (capacity 650 mm diameter), smaller sibling to the U4000W launched at MACH 2014. Instead, the focus was on new capabilities, to a greater or lesser degree software-based.
In some of these, NCMT has played a key development role. For example, it showed the EasyGrind Max PC software on the Makino iGrinder G5 and G7, that, for the first time, incorporates a CAD system, so models can be imported, and also has a simulation package. NCMT says that the latter feature removes the need to run software such as CGTech's Vericut (01273 773538) to prove out a cutting path. The software was developed by the European Makino and NCMT marketing joint venture Makino-NCMT Grinding Division, and launched in March. The iGrinder range uses the VIPER creep-feed grinding process developed by Makino and Rolls-Royce.
Also demonstrated on an iGrinder G7, and coming up for launch as an option with new machines or as a retrofit, is analysis software Easygrind Max Process Developer. This records spindle power 250 times per second, charting power versus time on the machine's control (data which can, of course, be exported). Its purpose is to help users improve grinding performance by choosing the optimum processes and materials.
"It's very difficult to understand what's going on [during grinding]," points out NCMT engineering director Adrian Maughan. "You can't see an awful lot; you've got all of that coolant: 70 bar, 150 l/min. And with these new materials as well, how do you develop a process, how do you know when the wheel is loaded; when do you need to dress; how do you compare one wheel against another? We're trying to put some science behind it. We're building up our experience, as regards how to read this data."
This kind of grinding process documentation is likely to be required more and more by customers, according to Maughan, who envisages that customers will in future demand records of not only spindle power but also coolant pressure, coolant flow and coolant temperature, on a routine basis for each part ground. That way, any burning problems discovered later on the part could be diagnosed.
In the meantime, Easygrind Max Process Developer has already proved its worth. Makino-NCMT engineers have found that spindle power is associated with cracking in a particular new aerospace material, and so has chosen grinding wheels that require the minimum amount of spindle power to finish the job. The metal studied is gamma titanium aluminide, on which Makino-NCMT has spent two years developing machining processes. Intended for use in aero engines, it is very light (half the weight of Ti64), has good high temperature properties (resistant to oxidation and corrosion up to 600 ºC), but behaves in a very different way to nickel alloy. "We're finding it cracks very easily," Maughan offers.
Also, GE Power & Water (Hungary) is using an iGrinder G7 machine to make aerospace blades from a nickel alloy, reports sales director Laurence Ireland. The machine is configured in an auto-loading cell. Previously the parts were milled; switching to grinding has generated a "huge" saving, he says.
In fact, aerospace has been NCMT's main business over the last year or so, accounting for 60-70% of turnover. Managing director Dave Burley says that aeroengine and aerospace are in a bubble – "a really good bubble" – so business has been strong. Its strength has helped balance the loss of business caused by the oil price drop, which has reduced capital expenditure in oil and gas, where NCMT had recently had some successes.
Other capabilities shown at the event – some new, some not so new – were developed by the manufacturers NCMT represents and have been rolled out globally.
The Blue Photon workholding system is for awkwardly-shaped parts
For example, new to NCMT and the UK is Blue Photon, a resin-based adhesive that claims to hold awkwardly-shaped parts for machining without distorting them, as clamping might. Users apply the glue to the ends of 15 mm diameter gripper pins, which have hollow centres carrying a fibre-optic cable termination that is connected to a UV source. The light cures the glue in one minute. NCMT says that the technology, developed at Pennsylvania State University, has a holding strength of 136 kg per pin. To break the connection, users could torque the pins with a socket wrench to shear them off the surface, or wash the workpiece in hot water; the adhesive is water-soluble. NCMT is now the agent for all of Europe, except Spain, which is covered by a prior dealership arrangement.
On another Makino VIPER grinder, the A99e, a new in-process probing cycle from Delcam (0121 766 5544) used for prove-out was demonstrated. A Renishaw probe was programmed using Delcam on-machine verification software to check surfaces while the part is still clamped on the machine, eliminating the need to put the part in a CMM and then return it to the machine for more metal removal after an extensive re-clocking process.
Across the showroom, there was a new-to-the-UK twin-pallet version of the Okuma MA600HII horizontal machining centre. It held a manifold-type test piece, used to demonstrate the Okuma TurnCut process that, although not new (it launched at EMO in 2007), is interesting. The TurnCut system enables the machine to cut circular seals and other conventionally turned features, such as inner and outer diameters, as well as supporting deep-hole drilling, ACME threadcutting and screw threading, the latter using standard turning tools.
Unlike a conventional turning process, the machine orbits the tool about or within a static workpiece. The secret weapon is the control of the machine's horizontal spindle that interpolates X and Y as it feeds into a stationary part (in Z); the spindle axis rotates as the spindle orbits, orientating the tool tip at the correct rake angle.
Other Okuma machines demonstrated the manufacturer's existing 'Smart Technology', including its Collision Avoidance System (Multus B400IIC lathe); 5-axis Auto Tuning system (MU-6300V-L millturn); Thermo-Friendly (MA600HII); and Machine Navi anti-chatter system (Space Turn LB 3000 EX lathe).
School trip builds on founder's legacy
On Friday, 15 May, NCMT opened the exhibition to local students and apprentices. More than 50 teenagers from three nearby schools were invited, in hopes of stimulating their interest in manufacturing, and even possibly a career with NCMT. "We are struggling to find apprentices," says NCMT managing director Dave Burley. "Graduates are fine in front of FEM software but they have no understanding of how to make parts, how material moves when you clamp it and of tolerancing. We're better off with youngsters." NCMT has three apprentices, each of which gave a presentation to the group that also included first-year apprentices from local college Midland Group Training Services. Later this year, the 100-employee company will take on another apprentice, with funding assistance from the Thomas Gerald Gray Charitable Trust set up in 2012 by the widow of NCMT's founder.
First published in the June 2015 edition of Machinery
